What are the chances of having another set of twins?

[ObiJuanKenobi]

Our twin boys are turning 2 and we have just started discussing having another baby.
We have DCDA twins so I believe there is a reasonable chance it could happen for us again.

Does anyone know what the odds actually are? Is there a set 1 in 10000 type stat out there? I've googled and found lots of contradictory info!

DCDA twins can be fraternal (two eggs, two sperm) or identical (one egg, one sperm). All fraternal twins will be DCDA, while identical twins can be DCDA, MCDA or MCMA depending on the stage when the blastocyst splits.

If your twins are identical, then the odds of having another set of twins is the same as any other pregnancy because identical twins are a random fluke of nature.

If your twins are fraternal, then you have proved yourself to have released two eggs on at least one occasion. The odds of twins again is therefore increased, as the chances of you releasing two eggs is higher than in someone who we don't know to have released two eggs on any occasion.

When I was pregnant with my twins, I heard that there is a 1:89 chance of fraternal twins in a normal pregnancy, with a 1:4 chance of fraternal twins for a mother who already has fraternal twins. I think I read it in "Your Pregnancy Week by Week" by Lesley Ragan, who is a mother of twins herself, but I can't be certain that was the source.

Anecdotally, my second pregnancy was a single baby

I am a twin and have 1 set of twins I was told at most 1 in 4

Fraternal twins here, yes I remember now if the egg splits in the first couple of days identical twins can still be DCDA, I think there was so much info to take in at the time it all went a bit over my head.

That's a lot higher than I thought it would be!! I wouldn't mind having twins again at all, or a singleton, but perhaps would wait a little longer until these two are slightly older before trying again - I imagine the logistics of two sets of twins under 3/4 would be tricky.

I can't find a source right now but I believe the chances of fraternal twins also increases with the mother's age from the age of 35 onwards. So your own age might also be relevant.

I'm a fraternal twin. Also told 1:4

How old are you? The chance of fraternal twins increases steadily with maternal age from 35+.

Do the odds increase if you're a fraternal twin yourself?

Radiographers can always tell when a women has had twins previously. Not questions like 'what sex is it?' just repeated 'are you sure there is just one?'

I got told 1 in 4 also.

dinosaur Yes.

is there a logic to the 1:4 chance, or is it based on observation?
I had fraternal twins and GP poopoohed the notion that my next pg might be twins, despite the fact that every other person I spoke to had a cousin who had twins and then went on to have triplets. He did send me for an early scan though, bless him.

Remember it being high odds once you've had fraternal twins with likeliness increasing with age and subsequent pregnancies.

But my number 3 was just one, not twins again.

Well yes, plus the fact that your first set of fraternal twins might indicate that you have a genetic predisposition to release multiple ova. That’s why a woman with previous fraternal twins have a higher chance than a woman of the same age with previous single pregnancies.

*has

I'm mid 20s and not a twin myself, there were lots of twins further up the family tree but no record of any subsequent siblings for any - not sure if there were any and the family tree isn't accurate or not.

It's all very interesting stuff thank you for your input!

Forgive me if you know this - but fraternal twins (unless they're identical twins that split very early) are genetic. They often run in the mother's maternal family - the release of 2 eggs.

I'm a fraternal twin and have had fraternal twins. My twin sister has also had fraternal twins. My aunt (on my mother's side) was also pregnant with fraternal twins but lost one early in pregnancy.

"If your twins are identical, then the odds of having another set of twins is the same as any other pregnancy because identical twins are a random fluke of nature."

Not relevant to the OP, but actually the likelihood of having monozygotic ("identical") twins is probably weakly heritable as well. Research is currently ongoing, but some populations and families have usually large numbers of identical twins, suggesting that there may be a genetic predisposition towards the splitting of blastocysts in some women.

@Kokeshi123 there's a family in my twin club with two sets of identical twins actually!